AstraZeneca has concluded the acquisition of the US-based clinical-stage biopharmaceutical company Icosavax in a $1.1bn deal.

The latest development comes after the companies entered a definitive agreement to execute the acquisition in December 2023.

The deal, which was finalised through a tender offer for all outstanding shares at $15 each plus additional contingent value rights, will bolster AstraZeneca’s late-stage pipeline.

Icosavax focuses on the development of differentiated vaccines with greater potential using its protein virus-like particle (VLP) platform.

The company will function as an AstraZeneca subsidiary with its operations in Seattle, US.

AstraZeneca will add IVX-A12, a lead investigational combination protein VLP vaccine candidate of Icosavax, to its vaccines and immune therapies late-stage pipeline.

The acquisition will strengthen AstraZeneca’s position in the respiratory syncytial virus (RSV) space and is expected to support the progression of IVX-A12, a Phase III-ready vaccine targeting both RSV and human metapneumovirus (hMPV).

RSV and hMPV are significant causes of severe respiratory infections and hospital admissions, particularly among adults aged 60 and above and individuals with chronic ailments.

Phase II trial data showed that IVX-A12 induced strong immune responses against RSV and hMPV a month following vaccination, validating the prior immunogenicity findings from the Phase I trial.

IVX-A12 was also well-tolerated in the Phase II trial demonstrating a safety profile in line with the Phase I study.

It has received fast-track designation from the US Food and Drug Administration (FDA).

The integration of Icosavax's capabilities in protein design and VLP science into AstraZeneca’s operations will create a platform for developing vaccines against high-burden respiratory conditions.

The FDA previously approved AstraZeneca’s Tagrisso plus chemotherapy for locally advanced or metastatic non-small cell lung cancer with epidermal growth factor receptor mutations in adults.